Elicitor mediated enhancement of wedelolactone in cell suspension culture of Eclipta alba (L.) Hassk

Abstract

The present research focused on enhancing the production of wedelolactone through cell suspension culture (CSC) in Eclipta alba (L.) Hassk. With an aim of attaining a sustainable CSC, various plant growth regulators, elicitors and agitation speed were examined. Nodal segments of in vitro propagated plantlets induced the maximum percentage (93.47 ± 0.61%) of callus inoculated on Murashige and Skoog (MS) medium fortified with picloram (2 mg L−1). The growth kinetics of CSC exhibited a sigmoid pattern with a lag phase (0–6 days), a log phase (6–18 days), a stationary phase (18–24 days) and then death phase thereafter. The highest biomass accumulation in CSC with 7.09 ± 0.06 g 50 mL−1 fresh weight, 1.52 ± 0.02 g 50 mL−1 dry cell weight, 1.34 ± 0.01 × 106 cell mL−1 total cell count and 57.00 ± 0.58% packed cell volume was obtained in the liquid MS medium supplemented with 1.5 mg L−1 picloram plus 0.5 mg L−1 kinetin at 120 rpm. High performance thin layer chromatography confirmed that yeast extract (biotic elicitor) at 150 mg L−1 accumulated more CSC biomass with 1.22-fold increase in wedelolactone (288.97 ± 1.94 µg g−1 dry weight) content in comparison to the non-elicited CSC (237.78 ± 0.04 µg g−1 dry weight) after 120 h of incubation. Contrastingly, methyl jasmonate (abiotic elicitor) did not alter the biomass but increased the wedelolactone content (259.32 ± 1.06 µg g−1 dry weight) to an extent of 1.09-fold at 100 µM. Complete plantlet regeneration from CSC was possible on MS medium containing N6-benzyladenine (0.75 mg L−1) and abscisic acid (0.5 mg L−1). Thus, the establishment of protocol for CSC constitutes the bases for future biotechnological improvement studies in this crop.